1. Field of the Invention
The present invention relates to a circuit arrangement for driving an IC module by output digital signals of another IC module, and is particularly concerned with such a circuit arrangement in which mutually identical input circuits are provided for the individual data signals, the respective switching threshold of the input circuits being set based on the measure of the DC component appearing in a representative digital signal, being controlled by a control signal shared by the input circuits and comprising a limiter charged by a digital signal whose signal level is also representative for the remaining digital signals and comprising a low-pass filter following the limiter and leading to the control inputs of the input circuits.
2. Description of the Prior Art
Various circuit technologies have been developed with respect to integrated digital circuits which respectively do justice to a particular degree to specific requirements to be made of integrated circuits, but thereby are usually burdened with other, disadvantageous properties. Therefore, the emitter coupled logic (ECL) technology which has long been utilized is particularly distinguished by the speed and the response sesitivity of its circuits, this, however, involving relatively high stray energy and a low protection against malfunction. Resulting therefrom is that ECL technology can hardly be replaced at present in certain applications, for instance in line drivers and line receivers, but that there is a simultaneous tendency to at least realize other circuit portions with large scale integrated (LSI) digital circuits of other technologies, for example in complementary-metal-oxide-semiconductor (CMOS) technology, which, on the one hand, can also be adequately fast and wherein, on the other hand, the power consumption is far lower. However, it is then not yet adequate to merely provide fast input circuits, for example CMOS inverters, at the interfaces between ECL technology and CMOS technology. On the contrary, such fast CMOS input circuits must also be supplied with the correct digital signal level. This can be effected by an appropriate level balancing in an interface circuit, whereby, however, a simple level matching is frequently inadequate in practice, but level fluctuations, do, for example, to feed voltage fluctuations and temperature changes, must also be avoided.